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Gyrus cinguli
| Latin = gyrus cinguli | GraySubject = | GrayPage = | Image = Gray727.svg | Caption = Medial surface of left cerebral hemisphere. | Image2 = | Caption2 = | IsPartOf = | Components = | Artery = | Vein = | BrainInfoType = hier | BrainInfoNumber = 141 | MeshName = Gyrus+Cinguli | MeshNumber = | DorlandsPre = g_13 | DorlandsSuf = 12405192 | }} of brain. Cingulate cortex is shown in yellow.]] The cingulate cortex is a part of the brain situated in the medial aspect of the cortex. It includes the cortex of the cingulate gyrus, which lies immediately above the corpus callosum, and the continuation of this in the cingulate sulcus. The cingulate cortex is usually considered part of the limbic lobe, separate from the adjacent frontal and parietal lobes. It receives inputs from the thalamus and the neocortex, and projects to the entorhinal cortex via the cingulum. It is an integral part of the limbic system, which is involved with emotion formation and processing, learning, and memory, and is also important for executive function and respiratory control. History Cingulum means belt in Latin. The name was likely chosen because this cortex, in great part, surrounds the corpus callosum. Cingulate is an adjective (cingularis or cingulatus). The cingulate cortex is a part of the "grand lobe limbique" of Broca (1898) that consisted (in addition to the olfactory part, which is no more considered there today) of a superior cingulate part, supracallosal; and an inferior hippocampic part, infracallosal. The limbic lobe was separated from the remainder of the cortex by Broca for two reasons: first that it is not convoluted, and second that the gyri are directed parasagittally (contrary to the transverse gyrification). Since the parasagittal gyrification is observed in non-primate species, the limbic lobe was thus declared to be "bestial". As with other parts of the cortex, there have been and continue to be discrepancies concerning boundaries and naming. Brodmann (1909), a student of Cécile Vogt-Mugnier and Oskar Vogt, who worked on cercopithecus (and not much in human (Bailey and von Bonin)), elaborated a system of numeration that had unfortunately no typological logics (1, 2 and 3 are sensory, 4 is motor, 5 is parietal, 6 is premotor and 7 is again parietal!). Area 25 was even not placed by him in the same place in the human brain. Area 24 (anterior) was distinguished from 23 (posterior) on the basis that it was agranular. More recently, the typographical von Economo's system was adopted by Bailey and von Bonin. Simple typographical naming should be preferred, for evident heuristic purposes. Subdivisions Based on cerebral cytoarchitectonics it has been divided into the Brodmann areas 23, 24, 26, 29, 30, 31 and 32. The areas 26, 29 and 30 are usually referred to as the retrosplenial areas. Anterior cingulate cortex This corresponds to area 24 of Brodmann and LA of Constantin von Economo and Bailey and von Bonin. It is continued anteriorly by the subgenual cortex (area 25). It is cytoarchitectonically agranular. It has a gyral part on the surface and a sulcal part. Anterior cingulate cortex can further be divided in the perigenual anterior cingulate cortex and midcingulate cortex. The anterior cingulate cortex receives primarily its afferent axons from the intralaminar and midline thalamic nuclei (intralaminar and midline of the thalamus, see thalamus). The nucleus anterior receives mamillo-thalamic afferences. The mamillary neurons receive axons from the subiculum. The whole forms a part of Papez' circuit. The anterior cingulate cortex sends axons to the anterior nucleus and through the cingulum to other Broca's limbic areas. The ACC is involved in error and conflict detection processes, such as in the go/no-go task. Posterior cingulate cortex This corresponds to area 23 of Brodmann LP of von Economo and Bailey and von Bonin. It is granular. It is followed posteriorly by the retrosplenial cortex (area 29). Dorsally is the granular area 31. The posterior cingulate cortex receives a great part of its afferent axons from the superficial nucleus (or nucleus superior- falsely LD-) of the thalamus (see thalamus), which itself receives axons from the subiculum. To some extent it thus duplicates Papez' circuit. It receives also direct afferents from the subiculum of the hippocampus. Cingulum and interconnections At the base of the cingulate cortex is a thick parasagittal bundle, the cingulum. It strongly increases in evolution, and in humans it can even be dissected. The cingulum is used for the connections of the two subdivisions described above and with the parahippocampal gyrus. The cingulate cortex can also be differentiated based on its thalamic connections: Midline and intralaminar nuclei. Function It functions as an integral part of the limbic system, which is involved with emotion formation and processing, learning, and memory. Also, executive control needed to suppress inappropriate unconscious priming is known to involve the anterior cingulate gyrus. See also * Brodmann area 24 * Cingulate sulcus * Cingulate cortex * Papez circuit References * Pain Stimuli Recorded Over the Human Anterior Cingulate Gyrus, Lenz, et al. External links * * Category:Cerebrum Category:Frontal lobe Category:Limbic system